Katy Perry shines bright on her latest Billboard cover in advance of the release of 'Prism.' But she had to wade through the darkness --a divorce, shade from Barbara Walters and suicidal thoughts-- to get here.

While she stated that she is "masquerading as a pop star" who might end up more like a Joni Mitchell type since "Madonna's never going to give me that damn baton," Perry pulled back the curtain on her personal life in the interview. She also revealed that the second single and follow up to 'ROAR' will be 'Unconditionally.'

She also shared that Barbara Walters, the doyenne of interviewers next to Oprah Winfrey, threw shade at her due to her being late for their interview as her marriage to Russell Brand was crumbling.

"I shouldn't have done the interview," Perry recalled about the chat with Babs. "I was playing Madison Square Garden that same night, and I knew that the end of my marriage was coming. I was just exhausted and stressed. I'd prepped everyone that I was running late, but Barbara showed up at the original time anyway."

She further revealed, "When I got there, I apologized immediately, but then she said to me, 'You know, I've only ever waited for one other person this long, and you know who that person was? Judy Garland. You know how she turned out, right?' I was like, 'Oh, snap! Yes, b---h!' I think it's the coolest thing that Barbara Walters shaded me. I just couldn't tell her as we were sitting down for a mega-interview, 'Hey, my marriage is falling apart. Give me a break.'"

Here's five more things we learned from the interview.

She considered suicide: The song 'By the Grace of God' is autobiographical and is about the time Perry found herself lying on the bathroom floor, pondering ending it all. "That song is evident of how tough it really was at a certain point. I asked myself, 'Do I want to endure? Should I continue living?' All the songs are real-life moments. I can only write autobiographically. I put all the evidence in the music. I tell my fans if they want to know the real truth about stuff, just listen to the songs."

'Prism' does have a song about her divorce: The song 'Ghost' features the line "You sent a text/ It's like the wind changed your mind," which refers to how Brand let her know he wanted to end the marriage.

Her BF John Mayer also factors into 'Prism': Mayer has a songwriting credit on 'Spiritual.' He plays guitar on 'It Takes Two.' She also said he gave her the title, since it refers to her spectrum of emotions.

She thinks Mayer is a genius: "I always tell him, 'Darling, you know I'm going to have to give your mind to science after you've passed, because we're going to have to understand how all these sparks work.' We'll be in bed, and he'll be doing the crossword puzzle. Every night, he tries to finish it in under 10 minutes. When he puts his mind to something, he really gets it done very well. I always ask for his help."

Mayer gives good advice: "One thing John said to me was, 'It's harder maintaining success than finding it.' I've got a few records under my belt, and I still feel like a brand new artist. People still want that truth to cut through."

Perry also discussed the fact that she had said that her new album would be darker in 2012 interviews. Now, she has changed her tune and the tunes, reflecting light.